It's just mathematical equivalency
We need to remember that the universe doesn't really run on mathematical formulae - they are just models. Electrons don't do a quick calculation before deciding how much energy to emit as a photon when changing orbitals. It all "just happens" and we try to model it with equations that have predictive power.
We already know our perception is just a simulation built inside our heads. For one thing, the bandwidth of our optical and auditory systems is not nearly enough to present a full video and audio recording of the perceived world, yet we have that illusion.
So arguments about whether the universe is a "simulation" are nonsensical. The universe is what it is. What matters is whether it can be modelled more conveniently and more accurately with a different model, just as Newton's laws allowed planetary orbits to be calculated more simply and reliably than did epicycles. The general relativistic universe is just a better simulation than the Newtonian universe, and that's a much better simulation than the Copernican universe. But they are all simulations, and our perception of the world is another one.